Question: A is thrice as good as workman as B and therefore is able to finish a job in 60 days less than B. Working together, they can do it in:
[A].
20 days |
[B].
|
[C].
25 days |
[D].
30 days |
Answer: Option B
Explanation:
Ratio of times taken by A and B = 1 : 3.
The time difference is (3 – 1) 2 days while B take 3 days and A takes 1 day.
If difference of time is 2 days, B takes 3 days.
| If difference of time is 60 days, B takes |
|
3 |
x 60 |
|
= 90 days. |
| 2 |
So, A takes 30 days to do the work.
| (A + B)’s 1 day’s work = |
|
1 |
+ |
1 |
|
= |
4 |
= |
2 |
| 30 |
90 |
90 |
45 |
| A and B together can do the work in |
45 |
= 22 |
1 |
days. |
| 2 |
2 |
